The web catalog shows only apps that can be installed on the current device, so you will not see any apps in desktop browsers and mobile browsers running on unsupported operating systems. Opening the catalog in such cases is only meaningful if you want to view or edit your user profile.

Due to some specifics of the Firefox browser for Android, it cannot be used to browse available Android apps. You can still use it to view and edit your profile.

You will always be able to see and review an app distributed by email even in a desktop browser. However, you will have to open the app download page on a suitable device to be able to install the app.

Due to some specifics of the Firefox browser for Android, it is not supported by AppManager and you will not be able to install an app using it.